Hepatic 123I-insulin binding kinetics in non-insulin-dependent (Type 2) diabetic patients after i.v. bolus administration

Insulin binding kinetics in the liver were studied in non insulin dependent (Type 2) diabetic patients, by i.v. bolus administration of 123I-insulin. Eight Type 2 diabetic patients were compared with six male volunteers. Uptake of 123I-insulin by liver and kidneys was measured by dynamic scintigraphy with a gamma camera during 30 min. Images of liver and kidneys appeared within 2-3 min after administration of 123I-insulin at a dose of 1 mCi (37 MBq). Peak radioactivity for the liver was found 7.5±0.2 and 6.9±0.3 min after injection for the healthy and the diabetic subjects, respectively (N.S.). The percentage 123I-insulin hepatic uptake was not significantly different for the diabetic and the healthy subjects. Although a large variation exists for maximal uptake of radioactivity within both groups, the data suggest that binding differences in the liver in Type 2 diabetic patients, as compared to healthy subjects, may not account for hepatic insulin resistance. (orig.)